64ed246d03
no issue - added an `externalRequest` lib - uses same underlying `got` module as our `request` lib - uses `got`'s `beforeRequest` and `beforeRedirect` hooks to perform it's own dns resolution for each url that's encountered and aborts with an error if it resolves to a private IP address block - includes a bypass for Ghost's configured url so that requests to it's own hostname+port are not blocked - updated v2 and canary oembed controllers to use the `externalRequest` lib
61 lines
2.2 KiB
JavaScript
61 lines
2.2 KiB
JavaScript
const got = require('got');
|
|
const dnsPromises = require('dns').promises;
|
|
const errors = require('@tryghost/errors');
|
|
const ghostVersion = require('./ghost-version');
|
|
const config = require('../../shared/config');
|
|
const validator = require('../data/validation').validator;
|
|
|
|
function isPrivateIp(addr) {
|
|
return /^(::f{4}:)?10\.([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})$/i.test(addr) ||
|
|
/^(::f{4}:)?192\.168\.([0-9]{1,3})\.([0-9]{1,3})$/i.test(addr) ||
|
|
/^(::f{4}:)?172\.(1[6-9]|2\d|30|31)\.([0-9]{1,3})\.([0-9]{1,3})$/i.test(addr) ||
|
|
/^(::f{4}:)?127\.([0-9]{1,3})\.([0-9]{1,3})\.([0-9]{1,3})$/i.test(addr) ||
|
|
/^(::f{4}:)?169\.254\.([0-9]{1,3})\.([0-9]{1,3})$/i.test(addr) ||
|
|
/^f[cd][0-9a-f]{2}:/i.test(addr) ||
|
|
/^fe80:/i.test(addr) ||
|
|
/^::1$/.test(addr) ||
|
|
/^::$/.test(addr);
|
|
}
|
|
|
|
async function errorIfHostnameResolvesToPrivateIp(options) {
|
|
// allow requests through to local Ghost instance
|
|
const siteUrl = new URL(config.get('url'));
|
|
const requestUrl = new URL(options.href);
|
|
if (requestUrl.host === siteUrl.host) {
|
|
return Promise.resolve();
|
|
}
|
|
|
|
const result = await dnsPromises.lookup(options.hostname);
|
|
|
|
if (isPrivateIp(result.address)) {
|
|
return Promise.reject(new errors.InternalServerError({
|
|
message: 'URL resolves to a non-permitted private IP block',
|
|
code: 'URL_PRIVATE_INVALID',
|
|
context: options.href
|
|
}));
|
|
}
|
|
}
|
|
|
|
// same as our normal request lib but if any request in a redirect chain resolves
|
|
// to a private IP address it will be blocked before the request is made.
|
|
const externalRequest = got.extend({
|
|
headers: {
|
|
'user-agent': 'Ghost/' + ghostVersion.original + ' (https://github.com/TryGhost/Ghost)'
|
|
},
|
|
hooks: {
|
|
init: [(options) => {
|
|
if (!options.hostname || !validator.isURL(options.hostname)) {
|
|
throw new errors.InternalServerError({
|
|
message: 'URL empty or invalid.',
|
|
code: 'URL_MISSING_INVALID',
|
|
context: options.href
|
|
});
|
|
}
|
|
}],
|
|
beforeRequest: [errorIfHostnameResolvesToPrivateIp],
|
|
beforeRedirect: [errorIfHostnameResolvesToPrivateIp]
|
|
}
|
|
});
|
|
|
|
module.exports = externalRequest;
|